Ken MacRury and I attended a presentation on a Bridgewater biomass proposal and a Dalhousie Agriculture Campus biomass proposal. The presentations were organized by the Ecology Action Centre.
Here are my thoughts:
Both proposals are co-generation and both are Comfit. Dal will sell power to the grid @ $.17/kwh and will heat the campus from the biomass boiler. BW will sell to the grid and heat at least the NSCC campus and hopefully the provincial building, the courthouse a new subdivision and possibly other commercial neighbours. Both have very high efficiencies due to the co-gen aspects. Both have to be up and running in the summer of 2018 to qualify for the Comfit contract.
- They will gasify the wood fibre. The gas will fire the generators. The by product will be charcoal which they will sell to agriculture outfits and for filtering. The proponent suggested that charcoal used as a soil amendment captures and sequesters additional carbon from the soil which might otherwise get into the atmosphere.
- They predict no emissions from the generators.
- 45% of the wood will be bark from Freeman’s mill. They will dry the bark at the plant using heat cast off from the gas generators
- 55% of the wood will be stem wood from the Medway Forest Coop or from other certified producers. The stem wood would be poplar or grey birch which apparently has no other market as these species don’t make good firewood. Selling to the biomass plant was said to be important to the success of the Medway Coop.
- They already have a wood chip boiler which has died and are replacing it with the new biomass boiler.
- They can’t burn much bark due to the high moisture content but are committed to buying local “sustainably harvested” stem wood
- They are well along and will probably meet their deadline due to the building already existing.
- The electricity generated will just about offset the entire campus consumption.
- They will have scrubbers to reduce the stack emissions
- They seem dedicated to doing this responsibly.
My personal opinion is that these projects can both be reluctantly supported. The bad aspect is the continued destruction of our forests which would be better left intact.
The good points are:
- High efficiencies due to co-gen
- Good use of bark in Bridgewater, Apparently Freemans have more bark than they know what to do with (although it mostly comes from clearcutting)
- Support of the Medway Coop which is trying to demonstrate excellent harvesting practices.
Syd Dumaresq, Chair Friends of Nature